A comparison of temperature, salinity, and chlorofluorocarbon observations with results from a 1° resolution three‐dimensional global ocean model

Abstract

We describe the ability of a moderate‐resolution global ocean model to simulate the general circulation and the ocean‐atmosphere exchange and redistribution of chlorofluorocarbons (CFCs). The model was spun up from climatological initial conditions and has been integrated for decades representing 1930 to the present. Climatological monthly mean winds were imposed during the spin‐up and first 50 years of the integration. From 1980, monthly mean European Centre for Medium‐Range Weather Forecasts (ECMWF) wind stress fields were used. We compare model results to cruise data and to long‐term mean observations and find good qualitative agreement in most areas. Overall, the model agrees reasonably well in regions where measurable CFCs have been observed, and the large‐scale model ventilation pathways appear realistic. One of the most conspicuous shortcomings is the small volume of Antarctic Intermediate Water in the model results. This leads to errors in the general water mass structure and in CFC concentrations in the model in other regions. Notable CFC differences are found in regions where deep water masses are formed and in the upper subtropical gyre regions in which the Kuroshio extension exists. The model oceanic CFC sink represents <1% of all CFCs produced since 1930 and is small relative to the stratospheric sink for these compounds.